\begin{{tabular}}{{c@{{\qquad}}c@{{\qquad}}c}}
	\toprule
	\multirow{{2}}{{*}}{{\raisebox{{-\heavyrulewidth}}{{}}}}
	    & \multicolumn{{1}}{{c}}{{(a)}}
	    & \multicolumn{{1}}{{c}}{{(b)}}
	\\
	    & Using aggregated rig types
	    & Using disaggregated rig types
	\\
	\cmidrule{{2-3}}
        $1-R^2$
        & {r2_agg_3}
        & {r2_disagg_3}
    \\
        $ SD(\tilde{{p}}_{{it}}) $
        & {p_tilde_agg_3}
        & {p_tilde_disagg_3}
    \\
        $ SD(\hat{{p}}_{{it}}) $
        & {p_hat_agg_3}
        & {p_hat_disagg_3}
    \\
    \bottomrule
\end{{tabular}}
